As noted in U.S. Pat. No. 4,088,122 for FIELD BURNING APPARATUS, of which Thomas R. Miles, co-inventor herein, was the inventor, in certain types of agriculture it is often desirable thermally to cultivate a field which has been cropped. For example, in the production of grass seed, it is desired to dispose of the excess grass stems after harvesting of the seeds and to sterilize the fields to dispose of weed seeds, insect pests and undesirable fungi spores. The apparatus of such patent was particularly designed for use in burning residue material remaining in seed grass fields in the Willamette Valley of Oregon after harvest of the seeds to accomplish such ends. The apparatus of such patent, however, proved to have limited economic effectiveness. It comprised a wheel supported, elongated hood to be drawn or propelled along a field. A draft inducing means was provided at the forward end of the apparatus to induce air flow from the sides and rear of the hood towards the forward end. An air blower was also arranged to discharge air into the rearward portion of the hood to provide additional air to assist in complete combustion of all the residue. Field residue was ignited at the forward end of the hood as the apparatus moved down a field. While the apparatus was effective in burning residue from fields that were quite dry, it was not effective when fields were damp from dew or rain and the operative period within a growing season is uneconomically short. As a result, open field burning has continued to be the preferred method of removing grass field residues in the Willamette Valley. However, the valley lies between the Coast Range to the west and the Cascade Range to the east and which, in the late summer and fall of the year, shelter the valley from persistent winds and inversion periods frequently occur, trapping smoke and other gaseous products. Consequently, severe restrictions have been placed upon the periods of burning and the acreage that can be open burned in an effort to restrict the amount of smoke that is generated. If weather conditions severely restrict the amount of permitted open burning, it places a severe economic burden on the grass seed farmer who will be forced to use expensive mechanical methods to remove the debris and expensive and sometimes inefficient methods of killing insect pests, weeds and fungi. More recently, because of the increasing concern over the health hazard of the smoke resulting from open field burning, there exists a strong effort to prohibit totally open field burning.